Expandable curler

ABSTRACT

An expandable curler is provided to facilitate hair winding, because strain imparted by the curler to the hairs no longer depends on the strain applied by the operator during winding and where possible differences in strain caused by humidity or by drying are compensated by the curler, which consequently expands or contracts itself. The curler includes a body split in two or more rigid longitudinal sectors forming together a winding surface to receive an amount of wound hairs in a contracted configuration. Locking members of the sectors are also included in the contracted configuration and an elastic member, housed inside said sectors, are configured to apply a predetermined elastic force on said sectors, expanding the winding surface and determining a strain state at the wound hairs until reaching a balance between inner elastic force and strain applied to the wound hairs, when the locking members are deactivated.

FIELD OF INVENTION

The preset invention is related to a curler of the expandable kind,generally used for curling the hairs either of a head hair, i.e. abraid, or possibly of a wig or a hair extension system as well.

BACKGROUND

The known expandable curlers generally involve a curler body having anexternal surface apt to receive wound hairs to be curled, dry or wet.

In the art, some examples of curlers are known, wherein the volumethereof can be modified. For instance, U.S. Pat. No. 5,020,552 A andU.S. Pat. No. 3,707,155 A disclose curler device to wind and curl hairshaving a collapsible cylindrical external surface.

In U.S. Pat. No. 3,707,155 A, the collapsibility is determined by theextraction of a rigid member from an external hose with flexible walls.In such a way, the hairs wound and tightened on the external surface ofthe hose can be released, to deposit a curling agent on the hairs, whichare then tightened again.

Instead, U.S. Pat. No. 5,020,552 A discloses a curler having a tubularstructure split in two half-shell movable from an expanded configurationto a retracted configuration and vice versa, thanks to an internalmechanical device. In such a way, the hairs are wound when the curler isexpanded, while the curler is then more easily extracted from the curls,when it is arranged in a retracted configuration.

In any case, the two above mentioned curlers have two workingconfigurations clearly distinct to each other: an expanded configurationand a retracted configuration. Another curler similar to the latter onesis disclosed in Japanese patent application No. JP 2000-060628 A.

Instead, Japanese patent application No. JP 2001-037528 A discloses acurler wherein the resilient tubular structure thereof is compressed bythe hairs very tightly wound therearound. In this way, the curlerstructure partly restores the strain imparted to wind the hairs aselastic strain stretching and tightening the wound hairs.

However, the use of a similar kind of curler is very uncomfortable forthe user, whose hairs are subjected to a strong and even painful strainthrough the winding thereof. Further, the strain provided by the curlerto the hairs is forcedly very limited. Another curler, having a workingvery similar to that of the latter, is disclosed in Japanese patentapplication No. 2005-026354 A.

Through all the above described curlers, the strain applied to the hairsthroughout the curling is determined by the strain imparted by anoperator in the winding operation, hence by his physical strength,notwithstanding the discomfort suffered by the user. It is understoodthat an operator with less skill, or with more or less strength in hishands, could subject the hairs to a different strain from curl to curl,and from user to user, thus obtaining results even remarkably differentto each other.

Another element which could influence the curling and make unpredictablethe results of the use of the curler is the resilience of the hairs,which varies from user to user and depends on the humidity condition ofthe hairs too. As a matter of fact, a wet hair becomes more resilientand the resilience variation is different from hair to hair. Hence,hairs wound around a curler and subsequently wetted, or vice versa, maybe subject to even remarkable variations in strain, which may, in somecases, almost thwart the curling effect and, in other cases, damage thehair structure for the excessive applied strain.

The amount of hairs on the braid to be wound and the thickness thereofalso influence the strain applied to the hairs in the winding operation.It is understood that the hairs outside the winding, according to theoperator's skill, may be subjected either to a greater or to a lesserstrain with respect to the inner hairs. This may render the curlinguneven and prevents the achievement of full-bodied swirls, well definedand uniform.

Finally, the heating conditions may also vary the resilience of hairsand thus the strain state thereof, and the same for the chemicaltreatments to which the hairs are subjected while they are wound.

SUMMARY

The technical problem underlying the present invention is to provide anexpandable curler able to obviate to the drawbacks mentioned withreference to the state of the art.

Such a problem is solved by an expandable curler comprising a curlerbody split in two or more rigid longitudinal sectors forming together awinding surface receiving an amount of wound hairs in a contractedconfiguration, characterized in that it comprises locking means of saidsectors in said contracted configuration and elastic means, housedinside said sectors, apt to apply on said sectors a predeterminedelastic force expanding the winding surface and determining a strainstate at the wound hairs until the reaching of a balance between innerelastic force and strain applied to the wound hairs, when said lockingmeans are deactivated.

With the above defined curler, the hair winding no longer requires aparticular skill, because the strain imparted by the curler to the hairsno longer depends on the strain applied by the operator throughout thewinding operation. Further, possible differences in strain caused by thehumidity or by the drying are compensated by the curler, whichconsequently expands or contracts itself. Ultimately, the curlerexpansion can transmit a strain state even through a remarkable braidthickness.

BRIEF DESCRIPTION OF THE DRAWINGS

More advantages and changes to the above defined invention will bedisclosed by the description of an embodiment of expandable curler,provided to an exemplificative and non limitative purpose with referenceto the annexed drawings, wherein:

FIG. 1 shows a partially sectioned perspective view of an expandablecurler according to the invention in an expanded configuration;

FIG. 2 shows a perspective view of the curler of FIG. 1 in a contractedconfiguration;

FIGS. 3A and 3B show cross-sections of the curler of the precedingfigures, in an expanded (3A) and contracted (3B) configurationrespectively, according to lines A-A and B-B of FIGS. 1 and 2respectively; and

FIGS. 4A and 4B illustrate, through respective perspective views, theuse of the curler of FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the figures, an expandable curler is indicated by 1 asa whole. It comprises a curler body determined by the matching of twohalf-shells 2, 3 embodying rigid longitudinal sectors, two in thepresent case, in which the curler body is split.

However, it is understood that the curler body can be split in a numberof longitudinal sectors even greater than two.

The half-shells 2, 3 also determine a substantially cylindrical windingsurface, defined by the curved free surfaces 4, 5 of the twohalf-shells, opposite to the inner surfaces 6, 7 of the two half-shell,intended to be matched to each other.

In the present embodiment, the shape of the curler body is cylindricalwith a circular section, but it is understood that various shapes arepossible, even conical, as long as they provide a winding surface apt toreceive wound hairs.

On said surface 4, 5 means for retaining hairs may be provided, e.g.pliers means, spring means (not shown) or unevenness on the surfaces,like corrugated profiles or pins creating a comb effect keeping thehairs locked in their wound configuration. However, it has to be notedthat the hairs can be locked wound by a superimpositions of coils woundat the start around the curler body. In such a case, smooth free surfacemay ease the sliding of hairs on them without damages.

Inside said half-shell 2, 3, the curler 1 comprises elastic meansprovided for applying on the half-shells 2, 3, i.e. the above sectors,an elastic force pulling them apart and expanding the winding surfaceproduced by them.

In the present embodiment, such elastic means comprises four helicalsprings 8 arranged between the inner surfaces 6, 7 of the half-shells 2,3 at the angular points of the inner surfaces.

It is understood that any elastic member, apt to apply an elastic forcepulling said sectors, in which the curler body is split, apart andexpanding the winding surface could be considered fit for this purpose.

For instance, helical springs with axis perpendicular to thelongitudinal development of the curler may be replaced by a leaf springor coil spring whose end coils act on the inner curved surface of thehalf-shells 2, 3. Alternatively, the half-shell 2, 3 may house inside acompressed elastic member, e.g. an elongated sponge or foam rubbermember, appropriately shaped to expand itself to pull said half-shells2, 3 apart.

Moreover, means for preventing the disengagement of the half-shells 2, 3may be provided, e.g. a spin-plug arrangement between the half-shellsdetermining an end stop, corresponding to the maximum expansion of thecurler 1. Otherwise, as in the present embodiment, the springs 8themselves can be connected to the half-shells 2, 3 to prevent theirdisengagement. Alternatively, the curler can have a closed externalenvelope, possibly water-proof to protect the inside of the curler,limiting the expansion of the two half-shells 2, 3 introducing a maximumextension corresponding to the maximum volume of the envelope.

Further, the curler 1 comprises means for docking the sectors, in whichit is split, in a contracted configuration, wherein the winding surfaceis minimal and wherein the half-shells of the present embodiment arematched against each other, in opposition to the elastic force keepingthem apart.

It is understood that so many other variations are possible for saiddocking means. In the present embodiment, such locking means comprises apair of clamps 9 which may be inserted, at each end of the curler, intosuitable notches or seats 10 formed in said half-shells 2, 3.

Among the possible alternatives, a single clamp may be cited,longitudinally extending across the curler body, two or more non-elasticrings or two rigid caps, apt to be fitted on the curler body ends, acord possibly inserted in suitable holes formed at each curler ends,which can be knotted to lock the curler body in a contractedconfiguration and then loosened to release it, a locking lever mechanismand so on.

Preferably, said docking means can act on the opposite ends of thecurler, to assure the contraction thereof, along the whole lengththereof.

Said elastic means are provided to establish a strain state into thewound hairs until the reaching of a balance between inner elastic forceand strain applied to the wound hairs, when said locking means aredeactivated.

The working of the elastic means 8 and of the docking means 9, 10 willappear in greater detail form the description of the procedure accordingto which the curler has to be used.

In connection with FIGS. 4A and 4B, at the beginning the docking means9, 10 are activated in opposition to the inner elastic force of theelastic means 8 trying to expand the curler from the inner.

In such contracted configuration, a braid T is winded around the curler1, the braid T being dry or wet, treated, pre-treated or even to betreated and so on. The hairs are locked on the winding surface 4, 5 ofthe curler 1 by superimposition of the first coils of the braid (FIG.4A).

The operation of winding can be carried out imparting any strain to thewound hairs. The size, i.e. the length and the thickness of the braid Tcan be any. At the winding end, the hairs can be locked by any kind ofconventional clip.

Then, the operator can deactivate the docking means, in this embodimentextracting the clamps 9 from their seats 10. In this way, the internalelastic means is activated, the elastic force thereof beingpre-determined by the elastic constant of the spring or of the springsinside the curler 1.

Thus, the curler 1 expands until the reach of a balance between theinner elastic force and the strain applied to the wound hairs. Hence, ifthe hairs have been tightly tightened, the expansion is minor, and ifthe winding is loose, the expansion is greater. In both cases, at theend the hairs are subjected to the same strain.

If, in the winding, the hairs are subjected to a modification of theelasticity thereof, e.g. because the hairs are wetted, dried orchemically treated, the curler adjust itself to the new hair elasticity.

At the end of the treatment, the curler can be manually compressed, andthe locking means can be re-activated, in the present embodiment byinserting again the clamps 9 in their seats 10. The contraction of thecurler 1 hence can ease the unwinding of the braid T at the end of thetreatment.

It is understood that the operator can select among a set of curlershaving different inner elastic constants, to apply more or less strainto the hairs, according either to the treatment to be carried out or tothe wished effect.

Further, it is understood that the achievement of a given strain statedepends only on the selected elastic constant, but not on the operator'sskill. Therefore, the operator may have less skill in this kind oftreatments.

Obviously, through this set, sizes, i.e. length and diameter, of thedifferent curler may vary and the elastic force thereof, i.e. the powerto strain the wound hairs, can be easily identified by a particularcolour and/or a pattern formed on the winding surface.

The above described curler 1 can be easily made in inert material, notchemically interacting with the hair, suitable for a mass production,e.g. by molding. The selected material can be plastic or metallic, e.g.aluminium. In the latter case, the curler may house also heating means,to be activated during the hair treatment for drying or to set thecurled shape thereof.

In the embodiment here described, the expansion occurs by mutualpulling-apart of the longitudinal sectors, but it is understood that thesame result may be achieved through a mutual relative rotation of thesectors around a longitudinal axis. The rotation may determine theoverall expansion of the winding surface by an internal cam profileguiding the longitudinal sectors and/or by a peculiar shape of eachsector.

To the above disclosed expandable curler a man skilled in the art, tomeet further and contingent needing, may introduce several additionalchanges or variants, all of them in any case falling within theprotection scope of the present invention, as defined by the annexedclaims.

1. Expandable curler (1) comprising a curler body split in two or morerigid longitudinal sectors (2, 3) forming together a winding surface (4,5) receiving an amount of wound hairs in a contracted configuration,further comprising locking members (9, 10) of said sectors (2, 3) insaid contracted configuration and an elastic member (8), housed insidesaid sectors (2, 3), configured to apply a predetermined elastic forceon said sectors (2, 3) expanding the winding surface (4, 5) anddetermining a strain state at the wound hairs until the reaching of abalance between inner elastic force and strain applied to the woundhairs, when said locking members (9, 10) are deactivated.
 2. Curler (1)according to claim 1, wherein the curler body is determined by matchingtwo half-shells (2, 3) forming said rigid longitudinal sectors. 3.Curler (1) according to claim 1, wherein the winding surface issubstantially cylindrical.
 4. Curler (1) according to claim 1, whereinthe curler body comprises retaining members that retain the hairs intheir winded configuration.
 5. Curler (1) according to claim 1, whereinthe elastic member comprises helical springs (8) inside said sectors (2,3).
 6. Curler (1) according to claim 1, wherein the curler bodycomprises retaining members that prevent the disengagement of saidsectors (2, 3).
 7. Curler (1) according to claim 1, wherein the lockingmembers (9, 10) act on opposite ends of the curler body, to ensure thecontraction along the whole length thereof.
 8. Curler (1) according toclaim 1, wherein the curler body is made of inert material, plastic ormetallic.
 9. Curler (1) according to claim 1, wherein the curler bodycomprises a heating element, to be activated during the hair treatmenteither to dry or to or to set the curled shape thereof.
 10. Curler (1)according to claim 1, wherein the expansion of the winding surface (4,5) occurs by mutual pulling apart of the longitudinal sector (2, 3). 11.Curler (1) according to claim 1, wherein said sectors (2, 3) expand thewinding surface (4, 5) by mutual relative rotation of the sectors (2, 3)around a longitudinal axis with respect to an internal cam profileguiding the longitudinal sectors (2, 3) and/or by a peculiar shape ofeach sector (2, 3).
 12. Set of curlers (1) as claimed in claim 1,wherein the elastic member has different elastic constants, to applymore or less strain on the hairs according to either the treatment to becarried out or the desired effect.